Kronzer VL, Westerlind H, Alfredsson L, et al. - Researchers investigated if there exists a connection of respiratory disease with rheumatoid arthritis (RA) occurrence. Particularly, they evaluated this link by RA serostatus and smoking exposure. Participants were 1,631 incident RA cases and 3,283 matched controls identified from the Epidemiological Investigation of Rheumatoid Arthritis study. Findings revealed an increased risk for both seropositive and seronegative RA in relation to the presence of respiratory diseases; but this was true only in nonsmokers. These observations raise the hypothesis that smoking and airway disease are related to the development of RA via partly different mechanisms.